Abstract
Questions
Which are the main sub-alpine and alpine grassland communities in the northeastern Greater Caucasus of Azerbaijan and what are their environmental and anthropogenic drivers?
Location
Grasslands at 1800 and 3500 m a.s.l. on northern macroslope of the Greater Caucasus in Azerbaijan near Shahdag Mt.
Methods
We established a randomized sampling design with stratification by geomorphology and altitude and validation using remote sensing data. The vegetation survey on 194 relevés in a nested plot design of up to 100 m² encompassed examiniation of various site conditions. We applied cluster and indicator species analysis for vegetation classification, and indirect multivariate ordination to assess vegetation–environment relationships.
Results
We classified 13 unranked communities in two sub-alpine groups and one alpine group, plus the very distinct vegetation around camp sites of semi-nomadic herders. Important drivers for vegetation differentiation are altitude as proxy for temperature, latitude as proxy for orographically founded differences in bedrock and precipitation, aspect, soil factors, such as content of organic matter and variables connected to land-use types and intensity (e.g. pasturing vs hay meadows, browsing tracks). In consequence, also effects on species richness are detectable. Furthermore, we found only partial concordance of our communities with existing vegetation classifications in the Greater Caucasus.
Conclusions
A state-of-the-art classification and ordination of regional high-mountain grassland communities and their environmental drivers fills a gap in knowledge about this vegetation. It is widely unknown to international audience and remained almost unstudied during the last 25 yr, when severe shifts in land use remarkably changed the natural conditions. The study can help to identify problems in current grassland management and their consequences for biodiversity conservation. Desirable changes towards sustainable grassland utilization require combined socio-ecological assessments beforehand.
